In some data storage devices which have magnetic hard disks, an actuator locking system has been provided. The actuator locking systems prevent a loss of data written on the disk. Rather than landing the head in the data recording region and risking a loss of data, the head attached to the actuator, is moved and stopped over the landing area on a disk. Once positioned over the landing area, the actuator supporting the head is locked so that the head does not move to a position over the data recording area even when a shock or vibration is received from the outside.
U.S. Pat. No. 4,647,997 discloses an actuator locking system having a rotatable vane, a locking member (latch finger) coupled with the vane, and a spring attached to the vane. The rotatable vane, positioned relative to a predetermined axis, receives an air flow caused by the rotation of the disk. The spring biases the vane in the direction opposite the direction of the air flow. The locking member engages with the lock position of the actuator when the head is over the landing area of the disk and when the air flow is not strong enough to move the vane against the bias force of the spring. The locking member disengages from the lock position of the actuator when the air flow is strong enough to move the vane against the bias force of the spring. The actuator locking system disclosed in this patent has a data recording disk and an additional disk to assure production of a strong enough air flow which in turn assures the disengagement of the locking member from the actuator.
The actuator locking system disclosed in the above U.S. patent has a number of shortcomings. Among the shortcomings is that an additional disk for producing the air flow is needed along with the data recording disk. As a result, the thickness and weight of the disk unit will increase.
An object of the present invention is to provide an actuator locking system which can assuredly disengage a locking member from an actuator in the presence of the airflow produced by one disk. An additional and related object is that such a mechanism provided without increasing a thickness and weight of a disk unit.